CVE-2021-43990Network attack vector

Service disruption via external XML entity resolution

Published Apr 20, 2022 · Updated Apr 16, 2025

XML external entity injection in FANUC ROBOGUIDE V9 Rev.T and earlier allows remote attackers to disrupt the host through crafted XML. The undisclosed XML-processing locus resolves an attacker-controlled external entity reference from the payload; neither FANUC nor CISA names the parser or code path. No privileges are required, but a user must interact with the attack mechanism; successful exploitation can corrupt data and impair the PC.

CVSS severity5.3
Medium
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML external entity injection in FANUC ROBOGUIDE V9 Rev.T and earlier allows remote attackers to disrupt the host through crafted XML. The undisclosed XML-processing locus resolves an attacker-controlled external entity reference from the payload; neither FANUC nor CISA names the parser or code path. No privileges are required, but a user must interact with the attack mechanism; successful exploitation can corrupt data and impair the PC.

The record

CVE
CVE-2021-43990
Published
Apr 20, 2022
Updated
Apr 16, 2025
Vendor
FANUC Corporation
Product
ROBOGUIDE
Classifications
CWE-611, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 20, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=All <v9.40083.00.05 (Rev T)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FANUC Corporation · ROBOGUIDEversion=All <v9.40083.00.05 (Rev T)

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
6.1CISA ICS-CERTCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H
2.6NIST NVDAV:N/AC:H/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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